1. Field of the Invention
This invention relates in general to apparatus and method for the start-up of reciprocal remote supply feeding of intermediate stations of the communication installation, wherein in a remote supply feed circuit designed for DC current series feeding, a series connection of two feed circuits is provided, which are interconnected by way of a feed wire pair, with each of the feed circuits containing a constant current source.
2. Description of the Prior Art
German Pat. No. OS 2,260,335 which corresponds to U.S. Pat. No. 3,868,484 discloses a start-up circuit.
During the start-up of a remote feed supply circuit which operates with feed from both ends and contains no switching apparatus for closing the remote feed loop, the remote feeding device located at the other end is also designed to be capable of being automatically connected from the first feed location. For purposes of protecting individuals, the switching on and connection process must be executed only after testing the remote feed circuit to assure that it is free from faults.
It is known to carry out such testing with the aid of a voice frequency signal which subsequent to actuation of a start key is transmitted in one of the two feed stations by way of the remote feed current path to the other feed station. In the case of correct reception of the signal, the remote feed device is then automatically put in operation.
This voice frequency method requires voice frequency generators and receivers as well as switching installations which are required as additional apparatus to that required for the remote feeding apparatus.